Search Publications
Characteristics of quasi-static potential structures observed in the auroral return current region by Cluster
André, M.; Buchert, S.; Kistler, L. M. +6 more
Temporal and spatial characteristics of intense quasi-static electric fields and associated electric potential structures in the return current region are discussed using Cluster observations at geocentric distances of about 5 Earth radii. Results are presented from four Cluster encounters with such acceleration structures to illustrate common as …
The X-Ray Spectrum of the z=6.30 QSO SDSS J1030+0524
Farrah, D.; McMahon, R.; Priddey, R. +2 more
We present a deep XMM-Newton observation of the z=6.30 QSO SDSS J1030+0524, the second most distant quasar currently known. The data contain sufficient counts for spectral analysis, demonstrating the ability of XMM-Newton to measure X-ray spectral shapes of z~6 QSOs with integration times >~100 ks. The X-ray spectrum is well fitted by a power l…
Dynamics and Radiation of Young Type-Ia Supernova Remnants: Important Physical Processes
Lundqvist, P.; Sorokina, E. I.; Blinnikov, S. I. +1 more
We analyze the physical processes that should be taken into account when modeling young type-Ia supernova remnants (SNRs) with ages of several hundred years in which forward (into the interstellar medium) and reverse (into the ejection) shocks propagate. We show that the energy losses in a heavy-element-rich ejection can be significant for SNRs ev…
A Bias in Optical Observations of High-Redshift Luminous Infrared Galaxies
Le Floc'h, E.; Charmandaris, V.; Mirabel, I. F.
We present evidence for the dramatically different morphology between the rest-frame UV and 7 µm mid-IR emission of VV 114 and Arp 299, two nearby (z~0) violently interacting luminous infrared galaxies (LIRGs). Nearly all LIRGs are interacting systems, and it is currently accepted that they dominate the IR emission at z>1. LIRGs located a…
Three-Dimensional Photoionization Structure and Distances of Planetary Nebulae. I. NGC 6369
Monteiro, Hektor; Heathcote, Steve; Schwarz, Hugo E. +1 more
We present the results of mapping the planetary nebula NGC 6369 by using multiple long-slit spectra taken with the Cerro Tololo Inter-American Observatory 1.5 m telescope. We create two-dimensional emission-line images from our spectra and use these to derive fluxes for 17 lines, the Hα/Hβ extinction map, the [S II ] line ratio density map, and th…
An XMM-Newton view of M101 - I. The luminous X-ray source population
Warwick, R. S.; Roberts, T. P.; Ward, M. J. +2 more
We present the first results of an XMM-Newton EPIC observation of the luminous X-ray source population in the face-on supergiant spiral galaxy M101. We have studied the spectral and temporal properties of the 14 most luminous sources, all of which have intrinsic X-ray luminosities exceeding the Eddington limit for a 1.4-Msolar neutron s…
A large X-ray flare from the Herbig Ae star V892 Tau
Micela, G.; Favata, F.; Giardino, G. +1 more
We report the XMM-Newton observation of a large X-ray flare from the Herbig Ae star V892 Tau. The apparent low mass companion of V892 Tau, V892 Tau NE, is unresolved by XMM-Newton. Nevertheless there is compelling evidence from combined XMM-Newton and Chandra data that the origin of the flare is the Herbig Ae star V892 Tau. During the flare the X-…
X-ray spectroscopy of the Hertzsprung-gap giant star 31 Com, observed with XMM-Newton
Peres, G.; Maggio, A.; Scelsi, L. +1 more
We have analysed the XMM-Newton X-ray spectra of the yellow giant 31 Com with the aim of deriving information on the coronal structures of this archetypical Hertzsprung-gap star. To determine the emission measure distribution vs. temperature, EM(T), and the elemental abundances of the coronal plasma, with an accurate line-based approach, we have d…
The Continued Spectral Evolution of the Neutron Star RX J0720.4-3125
Verbunt, Frank; Vink, Jacco; de Vries, Cor P. +1 more
We observed the isolated neutron star RX J0720.4-3125 with Chandra's Low Energy Transmission Grating Spectrometer, following the XMM-Newton discovery of the long-term spectral evolution of this source. The new observation shows that the spectrum of RX J0720.4-3125 has continued to change in the course of 5 months. It has remained hard, similar to …
Microlensing Candidates in M87 and the Virgo Cluster with the Hubble Space Telescope
Zurek, David R.; Zepf, Stephen E.; Lauer, Tod R. +4 more
The position of the giant elliptical galaxy M87 at the center of the Virgo Cluster means that the inferred column density of dark matter associated with both the cluster halo and the galaxy halo is quite large. This system is thus an important laboratory for studying massive dark objects in elliptical galaxies and galaxy clusters by gravitational …